package kr.hkit.powerjava.mission;

import java.util.Scanner;

public class Ifx {
	public static void main(String[] args) {
		int grade;
		
		Scanner input = new Scanner(System.in);
		System.out.print("점수를 입력하시오. ");
		grade = input.nextInt();
		
		if(grade >= 90){						//a
			System.out.println("A");	//t
		}else if(grade >= 80){			//f		//b
			System.out.println("B");	//t
		}else if(grade >= 70){			//f		//c
			System.out.println("C");	//t
		}else if(grade >= 60){			//f		//d
			System.out.println("D");	//t
		}else{							//f		//e
			System.out.println("F");
		}
	}

}
